This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. X-ray emission spectroscopy provides unprecedented access to information about the electronic structure of closed-shell metals such as Zn(II). XES allows one to probe the filled bonding molecular orbitals directly, thus providing information comparable to that obtained from photoelectron spectroscopy, but without the radiation damage that PES causes. To date, most studies of Zn XES have focused on ionic lattice complexes. We propose to develop a model library of Zn XES spectra for a selection of carefully chosen model compounds and to apply this library in a study of Zn-containing alkyl transfer enzymes.